\begin{tikzpicture}
    \tkzDefPoints{0/0/B, 2/0/C, 2/3/A}
    \tkzDefMidPoint(A,B)  \tkzGetPoint{D}
    \tkzDrawPolygon(A,B,C)
    \tkzDrawSegment(C,D)
    \tkzMarkAngle[size=0.6](A,C,D)
    \extkzLabelAngel[0.4](D,C,B){$1$}
    \tkzLabelPoints[right](A)
    \tkzLabelPoints[left](D)
    \tkzLabelPoints[below](B,C)
\end{tikzpicture}

